So you must talking about the circumference I guess.
3.14( pi) * diameter.
In this question, you're trying to make an equivalent expression.
Your expression should be similar to:
15g + 20h
One of the best ways to make an equivalent expression is by using the distributive property.
You would see they're both divisible by 5, so we would be using 5 in our expression.
Your expression should look like this:
5(3g + 4h)
Answer:
5(3g + 4h)
4(x+7)=8x-20
4x+28=8x-20
28=4x-20
48=4x
x=12